The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 21, 2025
Filed:
Jul. 17, 2023
Cypress Semiconductor Corporation, San Jose, CA (US);
Cypress Semiconductor Corporation, San Jose, CA (US);
Abstract
An AC-DC converter and method of operating the same is provided to sense negative voltage (NSN) on a synchronous rectifier (SR_DRAIN) on a secondary-side of the converter. The SR_DRAIN voltage is sensed and a first integration signal (volt-sec) generated based on a time and voltage for which the SR_DRAIN voltage is greater than a bus voltage (V) output from the secondary. When Volt-sec is greater than a reference voltage a volt-sec based NSN detect signal is generated. A second integration signal (integ_resetb) is generated based on the time for which the SR_DRAIN voltage is greater than V. A pulse width of integ_resetb is determined using a counter, and, when it exceeds a reference by a predetermined percentage, a counter-expiry signal is generated. The volt-sec based NSN detect signal and the counter-expiry signal are logically combined to generate a real NSN detect signal when one or both are present.